I've done all this and I'm still getting noise when I run the motor:

 

Common ground from starting battery to negative post on 24v battery

 

Lowrance is wired directly to starting battery. 

 

Clamp on ferrite chokes on all wires. 

 

Transducer mounted on transom, with wire running down driver side, and tm power wires are running down passenger side. 

 

2 things I haven't tried: using a standalone battery for the depth finder, and disconnecting the common ground and on board charger. 

 

Any suggestions? 

Have a ferrite choke installed on the trolling motor power cord (not a clamp on).  My X5 was driving me nuts till I had that done.

1 hour ago, Jig Man said:

Have a ferrite choke installed on the trolling motor power cord (not a clamp on).  My X5 was driving me nuts till I had that done.

I installed a clamp on onto the positive cable coming from the battery right at the plug on the bow. Do you mean the power cord that goes into the motor itself? I have nothing on that yet. 

On 8/5/2017 at 6:17 AM, Jig Man said:

Have a ferrite choke installed on the trolling motor power cord (not a clamp on).  My X5 was driving me nuts till I had that done.

What exactly did you do? What kind, where'd you get it, how to install? 

On 8/5/2017 at 6:17 AM, Jig Man said:

Have a ferrite choke installed on the trolling motor power cord (not a clamp on).  My X5 was driving me nuts till I had that done.

?

I ran the unit directly to it's own battery, and most of the interference is gone.

I was reading on another forum about the same type of interference.  The solution was to install a DPST switch between the charger and batteries.